The specific causes of lung cancer are not completely clear, but there are some high-risk factors. Research has shown that lung cancer is influenced by a combination of genetic defects and internal and external environmental carcinogens. It is undeniable that long-term heavy smoking is the most important carcinogenic factor for lung cancer, with the amount and duration of smoking being positively correlated with the incidence of lung cancer. Secondly, environmental factors, such as working with asbestos or in mining areas, are also very relevant to the incidence of lung cancer. Thirdly, irregular eating habits, rest, alcohol consumption, indoor combustion, coal smoke, fumes from kitchen cooking, and carcinogenic substances released from indoor decorations and materials are also related. Fourthly, the body's internal immune status, metabolic abnormalities, genetic factors, and chronic lung infections also have a significant impact.